Table 1. Clinical characteristics and prognostic factors of patients with clinical stage IA NSCLC who underwent surgery.
| Characteristics | No. of patients [%] | 5-year survival rate (%) | Univariate P value† | Multivariate analysis | ||
|---|---|---|---|---|---|---|
| HR | 95% CI | P value | ||||
| Total | 229 | 84.9 | ||||
| Age (years) | ||||||
| <67 | 119 [52] | 93.2 | 0.005* | 1 | ||
| >67 | 110 [48] | 76.5 | 2.591 | 1.043–6.434 | 0.04* | |
| Sex | ||||||
| Female | 98 [43] | 88.5 | 0.147 | Not included in the multivariate model | ||
| Male | 131 [57] | 82.0 | ||||
| Smoking history | ||||||
| Never-smoker | 125 [55] | 87.3 | 0.069 | Not included in the multivariate model | ||
| Ever-smoker | 104 [45] | 82.0 | ||||
| CEA | ||||||
| Within the normal range | 174 [76] | 87.7 | 0.02* | 1 | ||
| Elevated | 55 [24] | 75.5 | 1.368 | 0.603–3.106 | 0.453 | |
| FEV1% | ||||||
| >70 | 123 [54] | 86.2 | 0.387 | Not included in the multivariate model | ||
| <70 | 79 [35] | 83.6 | ||||
| Unknown | 27 | |||||
| Tumor laterality | ||||||
| Right | 130 [57] | 87.6 | 0.131 | Not included in the multivariate model | ||
| Left | 99 [43] | 81.6 | ||||
| Primary lobe | ||||||
| Upper or middle lobe | 160 [70] | 83.4 | 0.387 | Not included in the multivariate model | ||
| Lower lobe | 69 [30] | 88.6 | ||||
| Tumor size on chest CT (cm) | ||||||
| <2.0 | 156 [68] | 88.0 | 0.197 | Not included in the multivariate model | ||
| >2.0 | 73 [32] | 78.3 | ||||
| Histological type | ||||||
| Adenocarcinoma | 195 [85] | 87.8 | 0.006* | 1 | ||
| Non-adenocarcinoma | 34 [15] | 69.7 | 2.197 | 0.959–5.037 | 0.063 | |
| Lymphatic permeation | ||||||
| Absent | 158 [69] | 90.9 | 0.007* | 1 | ||
| Present | 71 [31] | 73.8 | 1.57 | 0.643–3.837 | 0.322 | |
| Visceral pleural invasion | ||||||
| Absent | 194 [85] | 89.0 | <0.001* | 1 | ||
| Present | 35 [15] | 58.4 | 2.605 | 0.969–7.008 | 0.058 | |
| N status | ||||||
| N0 | 207 [90] | 86.8 | 0.022* | 1 | ||
| N1–3 | 22 [10] | 66.8 | 2.782 | 1.018–7.599 | 0.046* | |
Numbers in parentheses indicate percentages. *, significance level; †, log-rank test. HR, hazard ratio; CI, confidence interval; CEA, preoperative serum carcinoembryonic antigen level, normal upper limit at 5 ng/mL; FEV1%, forced expiratory volume percent in 1 s; CT, computed tomography; N, lymph node.